9-(2-(2-piperidinyl)ethyl) and 9-(2-(2-pyrrolidinyl)ethyl)acridanes



United States Patent 3,449,334 9-[2-(2-PIPERIDINYL)ETHYL] AND 9-[2-(2- PYRROLIDINYL)ETHYL]A'CRIDANES Charles L. Zirkle, Berwyn, Pa., assignor to Smith Kline &

French Laboratories, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Continuation-impart of application Ser. No. 602,184, Dec. 16, 1966. This application Oct. 26, 1967, Ser. No. 678,209

Int. Cl. C07d 37/24; A61k 27/00 US. Cl. 260-240 12 Claims ABSTRACT OF THE DISCLOSURE 9-[2-(2-piperidinyl)ethyl] and 9-[2-(2-pyrrolidinyl) ethyl'Jacridanes, which may be further substituted at the 2, 3, or l0-positions, prepared by Grignard reaction at the 9-position of an acridine or 9-acridanone, in the latter case, the resutling olefin intermediate being hydrogenated to the acridane product. The compounds are sedatives.

This application is a continuation-impart of copending Ser. No. 602,184, filed Dec. 16, 1966, and now abancloned.

This invention relates to acridane compounds having pharmacological activity and to intermediates therefor. In particular, the invention relates to acridine compounds substituted at the 9-position thereof with a 2-heterocyclicethyl or Z-heterocyclic-ethylidene group.

The product compounds of the invention are represented by the following structural formula:

R1 5 1!: 4 e a CHsCH where X is hydrogen, chloro, bromo, trifluoromethyl, methyl, methoxy, methylthio, methylsulfinyl, methylsulfonyl, dimethylsulfamoyl, or cyano;

R and R are each hydrogen or lower alkyl of 1 to 4 carbon atoms; and

n is 0 or 1.

3,449,334 Patented June 10, 1969 The indeterminate position of the X substituent is intended to indicate that X may be at the 2 or 3-position.

A preferred group of compounds is represented by Formula II:

where X, R, R and n are as defined above, except that R is not hydrogen.

The product compounds of the invention are unique in having a heterocyclic substituted ethyl group bonded to the central carbon atom of the acridane nucleus, the heterocyclic group being bonded through one of its carbon atoms, rather than through the nitrogen atom.

These compounds are prepared in the following manner, reference being made to Chart A, below.

CHART A flu E f ClMgCHaCH N R11 it x x x y Hl n 4 4 am. J

IV v In Hlln ClMgCHzCH J K N N it Hiln V X X CHECH J CHaCH A 9-acridanone, optionally substituted at the 2 or 3-posi- They may be formulated for use by incorporating them tion (IV), is alkylated with a lower alkyl iodide, sulfate, into standard pharmaceutical dosage forms such as capor other halide, and then treated with a Grignard reagent sules, tablets, and injectables containing 0.5-500 mg., prepared from a 2-piperidinylethyl or 2-pyrrolidinyletliyl the exact dosage varying with the weight and age of the chloride, optionally alkylated at the nitrogen atom. The subject being treated and the severity of the condition. Grignard reaction is conducted at reflux temperature in a Among the pharmaceutical excipients which may be used solvent such as ietfahydl'ofullan and the resulting interare lactose, talc, gelatin, magnesium stearate, sodium carmedi'ate product distilled. Distillation insures that the boxyrnethylcellulose, and peanut oil. product consists exclusively of the olefin III, rather than Th following examples are intended to illustrate the the first-formed hydroxy intermediate, which it isolated 40 preparation of the compounds of the invention, but are can be catalytically reduced to the product. It may also ot intend d t limit the scope thereof. be converted to an acridinum salt by treatment with a mineral acid such as hydrochloric acid; this salt can then I EXAMPIJE 1 be reduced to the product using a hydride reducing agent or catalytically, using a conventional catalyst such as 10% 2 chlinpo 9 [2 (1 methyl 2 plpendmylkthynacndam palladium on charcoal, platinum oxide, or R'aney nickel. A Grlgnard reagent 1s formed under llltl'ogen from the An alternative method of preparation, the route used freshly liberated free base of 18.5 g. (0.0934 moles) of for the preparation of compounds where R is hydrogen, 2-(1-methy1-2-piperidinyl)ethyl chloride hydrochloride consists of the Caalkylation of Ian acridine (V1) with a d 1110165) of tllrnings in y piperidinyl or pyrrolidinyl ethyl Grignard reagent to give fun-an. To this Grignard reagent dissolved in about v100 ml. a product (Ia) where the 5-position nitrogen is unalkylf tetrahydrofurfln is fi as solid ated. moles) of Z-chloroacridine. The mixture is refluxed and The 2 and 3-substituted 9-acridanones and acridines stirred under nitrogen for 5 hours and aqueous ammonium are either described in the literature or are prepared by chloride added. The mixture is extracted with ether, the known methods (see .U.S. Patents 3,131,190; 3,043,842). extracts dried with K 00 and the solvent evaporated to In general, he acridanones are prepared by cyclizing the give an oil, which when treated with hexane solidifies; appropriately substituted diphenylamine-Z-carboxylic acid M.P. 88-90% Recrystallization from hexane gives the title with the aid of a cyclizing reagent such as polyphosphoric product.

acid ester or sulfuric acid. Acridines are prepared by Ahydrochloride salt is prepared by dissolving the prodcyclizing with phosphorus oxychloride, converting the re- 0 net in ether, adding a saturated ethereal solution of hysulting 9-chloro compound toa9-(p-toluenesulfonylhydradrogen chloride, and recovering and purifying the prezino) derivative, and treating with an alkali metal hydroxcipitated salt.

ide such as sodium hydroxide in aqueous ethylene glycol.

The diphenylamine 2-carboxylic acids are prepared by re- EXAMPLE 2 V gg iggggg gg g flg i g gg an amlme or an ammo- 2-trifluoromethyl-9-[2-( l-methyl-Z-piperidinyl) The acid addition salts of the product compounds are ethyn'lo'methylacndane conventionally prepared by reaction of the basic com- To a suspension of 52.4 g. (0.2 moles) of 2-trifluoropound with the acid, either or both of which may be in methyl-9-acridanone in 525 m1. of dimethyl sulfoxide at the form of ether, alcohol, or acetone solutions. 70 is added 11.9 g. (0.22 moles) of sodium methoxide.

The product compounds of the invention are seda- The mixture is heated for A hour at cooled to 40,

tives. They are active in mice and nats in oral doses of and 56.8 g. (0.4 moles) of methyl iodide added over 10 25-2OO mg./kg. when evaluated in the standard dose minutes. The mixture is heated at 75 for 1 hour, range test procedure in which the animals are adminquenched in water, and filtered. The recovered solid is istered a compound and observed for behavioral efiects. 75 dissolved in chloroform, filtered, and concentrated to a small volume. Addition of excess hexane gives the methyl ketone, M.P. 180-181".

To a Grignard reagent, formed from the liberated free base of 16.1 g. (0.0811 moles) of 2-(1-methyl-2-piperidinyl)-ethyl chloride hydrochloride and 1.9' g. of magnesium turnings in tetrahydrofuran, is added as a solid 15.0 g. (0.0541 moles) of the above ketone. The mixture is refluxed with stirring under nitrogen for 4-5 hours, aqueous ammonium chloride added, and the mixture extracted with ether. The ethereal extracts are extracted with 10% HCl, the acidic extracts basified, and the basified mixture extracted with ether. The oil obtained from drying and evaporating the ethereal extracts is distilled to give a yellow oil which is chromatographed with benzene on Woelm #1 basic alumina to give the olefin 2- trifluoromethyl-9-[':2-(l-methyl 2 piperidinyl)ethylidene]-IO-methylacridane, B.P. 192196/0.15 mm.

A mixture of 13.8 g. (0.0358 moles) of this olefin and 1.5 g. of 10% palladium on charcoal in 120 ml. of methanol is hydrogenated at 50 p.s.i. of hydrogen at 50 over 2 hours. The catalyst is filtered 01f and the solvent is evaporated to give, after distillation, the title product, B.P. 19 6-l99/ 0.15 mm. A hydrochloride salt is prepared as described in Example 1.

EXAMPLE 3 When the following listed acridines are condensed with the following listed Grignard reagent according to the procedure of Example 1, the corresponding listed products are obtained.

Acridine: 3-chloroacridine Grignard: 2-(2-piperidinyl)ethyl magnesium chloride Product: 3-chloro-9-[2- (2-piperidinyl) ethyl] acridane Acridine: 2-methoxyacridine Grignard: 2-(1-methyl-2-pi eridinyl)ethyl magnesium chloride Product: 2-methoxy-9- 2-( l-methyl-Z-piperidinyl ethyl] acridane Acridine: 3-bromoacridine Grignard: 2-(1-ethyl-2-piperidinyl)ethyl magnesium chloride Product: 3-bromo-9-[2-(l-ethyl-Z-piperidinyl)ethyl] acridane Acridine: 2-methylacridine Grignard: 2-(2-pyrrolidinyl)ethyl magnesium chloride Product: 2-methyl-9-[2-(2-pyrrolidinyl)ethyl]acridane Acridine: Z-trifluoromethylacridine Grignard: 2-(l-methyl-Z-pyrrolidinyl)ethyl magnesium chloride Product: 2-trifluoromethyl-9-[2-(l-methyl-2-pyrrolidinyl) ethyl] acridane Acridine: 2-chloroacridine Grignard: 2-( l-methyl-2-pyrrolidinyl)ethyl magnesium chloride Product: 2-chloro-9- [2-( l-methyl-Z-pyrrolidinyl ethyl] acridane EXAMPLE 4 When the following listed acridanones are condensed with the following listed Grignard reagents according to the procedure of Example 2, the corresponding listed intermediate products are obtained.

Acridanone: l0-methyl-9-acridanone Grignard: 2-(2-piperidinyl)ethyl magnesium chloride Intermediate: 9-[2-(2-piperidinyl)ethylidene]-10-methylacridane Acridanone: 2-methylthio-10-methyl-9-acridanone Grignard: 2-(l-methyl-Z-piperidinyl)ethyl magnesium chloride Intermediate: 2-methylthio-9- [2-( l-methyl-2-piperidinyl)ethylidene]-10-methylacridane Acridanone: 2-trifluoromethylsulfonyl-10-methyl-9- acridanone Grignard: 2-(l-ethyl-Z-piperidinyl) ethyl magnesium chloride Intermediate: 2-trifluoromethylsulfonyl-9- [2-( l-ethyl- 2-piperidinyl ethylidene] l0-methylacrid ane Acridanone: Z-dimethylsulfamoyl-10-methyl-9- acridanone Grignard: 2-(2-pyrrolidinyl)ethyl magnesium chloride Intermediate: Z-dimethylsulfamoyl-9-[2-(2-pyrrolidinyl)ethylidene]-10-methylacridane Acridanone: 3-chloro-10-ethyl-9-acridanone Grignard: 2-(l-methyl-Z-pyrrolidinyl)ethyl magnesium chloride Intermediate: 3-chloro-9- [2-( l-methyl-Z-pyrrolidinyl) ethylidene]-10-ethylacridane Acridanone: 2-trifiuoromethyl-10-ethyl-9-acridanone Grignard: 2-(1-ethyl-2-pyrro1idinyl)ethyl magnesium chloride Intermediate: 2-trifluoromethyl-9- [2-( I-ethyI-Z-pyrrolidinyl)ethylidene]-l0-ethylacridane I claim: 1. A compound of the formula CHnCHi or a pharmaceutically acceptable acid addition salt thereof, wherein X is at the 2 or 3-position and is hydrogen, chloro, bromo,

trifiuoromethyl, methyl, methoxy, methylthio, methylsulfinyl, methylsulfonyl, dimethylsulfamoyl, or cyano; R and R are each hydrogen or lower alkyl of 1 to 4 carbon atoms; and n is 0 or 1.

2. A compound as claimed in claim 1, wherein R is hydrogen or methyl.

3. A compound as claimed in claim 2, where R is hydrogen or methyl; and X is hydrogen, chloro, bromo, trifiuoromethyl, or methylmercapto.

4. A compound as claimed in claim 3, wherein R is methyl.

5. A compound as claimed in claim 4, wherein X is 2-chloro, R is hydrogen, and n is 1, being the compound 2-chloro-9-[2-(1-methyl-2 piperidinyl)ethyl] acridane or a pharmaceutically acceptable acid addition salt thereof.

6. A compound as claimed in claim 5, being in the form of the free base.

7. -A compound as claimed in claim 4, wherein X is 2-trifluoromethyl, R is methyl, and n is 1, being the wherein X is at the 2 or 3-position and is hydrogen, chloro, bromo,

trifluoromethyl, methyl, methoxy, methylthio, methylsulfinyl, dimethylsulfamoyl, cyano, or methylsulfonyl;

R is hydrogen or lower alkyl of 1 to 4 carbon atoms; and

n is 0 or 1.

10. A compound as claimed in claim 9, wherein X is hydrogen, chloro, bromo, trifluoromethyl, or methylmercapto; and R is methyl.

11. A compound as claimed in claim 10, wherein X is 2-chloro and n is 1, being the compound 2-chloro-9-[2- l-methyl-Z-piperidinyl)ethyidenel]-10-methylacridane.

12. A compound as claimed in claim 10, wherein X is Z-trifluoromethyl and n is 1, being the compound 2-trifluoromethyl 9 [2. (1 methyl 2 piperidinyDethylidene]-10-methylacridane.

References Cited UNITED STATES PATENTS 3,055,888 9/ 1962 Renz et a1. 260-240 3,131,190 4/1964 Zirkle 260-279 3,391,143 7/1968 Kaiser et al. 260-279 LEX MAYEL, Primary Examiner.

D. G. DAUS, Assistant Examiner.

US. Cl. X.R. 

